KR100643384B1 - Ink jet printer - Google Patents

Abstract

The present invention relates to an inkjet printer comprising an inkjet head portion for arranging a jet nozzle for injecting ink onto a printing paper, and printing predetermined print data on the printing paper, wherein the inkjet head portion has a horizontal direction of the center axis of the printing paper and the length of the inkjet head portion. A paper feeding portion which feeds the printing paper to the ink jet head portion inclinedly so as to form the predetermined angle; A measuring unit for measuring an inclination angle between the central axis of the printing paper fed by the paper feeding unit and the horizontal direction of the length of the inkjet head portion; And an adjusting unit that adjusts the print data according to the inclination angle measured by the measuring unit so as to be suitable for the printing paper fed obliquely. As a result, it is possible to improve the overall print quality by minimizing the degradation of print quality that may be caused by the spray nozzle having some performance deteriorated.

Inkjet printers, lineheads, slant feeds, shingling, quality improvements

Description

Inkjet Printers {Ink jet printer}

1 is a schematic view showing an inkjet printer according to a first embodiment of the present invention,

FIG. 2 is a schematic view showing a paper feeding unit of the inkjet printer of FIG. 1,

3 is a schematic view showing an inkjet printer according to a second embodiment of the present invention,

4 is a schematic view showing a paper feeding unit of the inkjet printer of FIG. 3.

* Explanation of symbols for the main parts of the drawings

10: inkjet head portion 12: jet nozzle

20, 20 ': Feeding section 22: Progress roller

24: inclined forming roller 26: approach roller

28: Feed direction change roller 30, 30 ': measuring part

40, 40 ': adjuster

The present invention relates to an inkjet printer, and more particularly, to an inkjet printer capable of minimizing a decrease in print quality even when the performance of some injection nozzles occurs.

An ink jet printer selectively sprays ink onto printing paper through an injection nozzle provided in the ink jet head portion to print a predetermined image. The jet nozzle jets ink intermittently under the control of the controller. The control unit causes the inkjet head portion to print predetermined print data on the printing paper by causing the ejection nozzle to inject ink at a specific position on the printing paper or to stop the ink ejection.

There are a plurality of jet nozzles in the ink jet head portion. Linewidth print head In the inkjet head portion of the printer, a plurality of ejection nozzles are arranged long to sufficiently cover the width of the printing paper.

Injection nozzles can be degraded for many reasons. Intensive and continuous spraying of ink can cause the spray nozzle to deteriorate. Alternatively, the injection nozzle may be clogged by the waste ink formed by drying the remaining ink remaining on the surface of the injection nozzle after cleaning the ink without cleaning. Alternatively, the performance of the spray nozzle may be degraded due to defects in manufacturing or other causes.

When the performance of the jet nozzle is degraded, sufficient ink is not jetted, and the image pixels of the print image in charge of the jet nozzle are not formed properly. As a result, the image quality of the entire printed image may be degraded. In particular, in the case where the ink jet head prints print data in which only a specific ejection nozzle is to intensively eject ink to form image pixels, such as print data corresponding to a straight line or black surface, if the specific ejection nozzle is degraded, Long straight lines that are not printed or not printed on the black side may occur, which may significantly reduce print quality.

Shuttle type inkjet printers have a method of compensating for the image quality caused by the performance degradation of some injection nozzles by shingling. By dividing the print data for image pixels adjacent to each other and printing them by different jet nozzles, the risk of deterioration in image quality significantly is dispersed as all of the adjacent image pixels are printed by the jet nozzles of which some performance is degraded. The technique for shingling of a shuttle type inkjet printer is disclosed in detail in Korean Patent Application No. 2001-81123.

However, in the case of the line head inkjet printer, the image quality cannot be compensated when the performance of some of the jetting nozzles is reduced. In order to improve the performance of the jetting nozzles, the entire inkjet head part needs to be replaced.

Accordingly, it is an object of the present invention to provide an inkjet printer capable of feeding the printing paper in an inclined direction or in an oblique direction so that the ink to be sprayed onto the printing paper to form adjacent image pixels is sprayed by different spray nozzles.

An object of the present invention is an inkjet printer comprising an inkjet head portion for arranging an injection nozzle for injecting ink onto printing paper, and printing predetermined printing data on the printing paper, wherein the center axis of the printing paper and the A paper feeding portion which feeds the printing paper to the ink jet head portion inclined such that a horizontal direction of the length of the ink jet head portion is a predetermined angle; A measuring unit for measuring an inclination angle between the central axis of the printing paper fed by the paper feeding unit and the horizontal direction of the length of the inkjet head portion; It is achieved by an inkjet printer including an adjusting unit for adjusting the print data according to the inclination angle measured by the measuring unit so as to be suitable for the printing paper fed obliquely.

The paper feeding portion has a rotational axis parallel to the lengthwise direction of the inkjet head portion, and is located between the traveling roller for advancing the printing paper to the inkjet head portion, and between the inkjet head portion and the traveling roller, It has a parallel axis of rotation and is arranged on an extension line having a predetermined angle with the ink jet head portion, and after advancing the printing paper so that the entry side of the printing paper to the inkjet head portion is inclined in the extension line direction It may include a plurality of inclination forming rollers formed to advance the printing paper.

In this case, the inclined forming roller is preferably formed such that the contact surface with the printing paper is convex, the point contact with the printing paper.

And a conveying unit for conveying the printing paper printed by the inkjet head unit to the paper feeding unit, wherein the paper feeding unit receives the printing paper from the conveying unit, and the printing paper is different from the inkjet head unit at different angles. Repeated feeding, the adjustment unit may shuffle the print data, and adjust each of the shingled print data according to the different angle.

An object of the present invention is an inkjet printer comprising an inkjet head portion for arranging a jet nozzle for injecting ink onto printing paper, and receiving printing data and printing on the printing paper. A paper feeding unit which advances the printing paper in a direction forming a predetermined angle with the paper and feeds the paper into the inkjet head unit; A measuring unit for measuring a feeding angle between the feeding direction of the printing paper and the transverse direction of the length of the inkjet head unit by the feeding unit; It is also achieved by an inkjet printer including an adjusting unit for adjusting the print data according to the feeding angle so as to be suitable for the printing paper fed in an oblique direction.

The paper feeding portion has a rotational axis parallel to a lengthwise direction of the inkjet head portion, and includes an access roller for accessing the printing paper to the inkjet head portion, and is located between the inkjet head portion and the access roller, and the rotation axis of the access roller. It may have a rotation axis having a predetermined angle, and may include a feed direction changing roller configured to receive the printing paper from the access roller and to feed the ink to the inkjet head portion.

The paper feeding direction changing roller is preferably formed such that the contact surface with the printing paper is convex, and is in point contact with the printing paper.

And a conveying unit for conveying the printing paper printed by the inkjet head unit to the paper feeding unit, wherein the paper feeding unit receives the printing paper from the conveying unit, and the printing paper is in the inkjet head unit in a different direction. Repeatedly feeding, the adjusting unit may shuffle the print data, and adjust each of the shingled print data according to the different direction.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention, an inkjet printer having a linehead (Linewidth printhead) is described as an embodiment.

1 and 2 are schematic diagrams showing an ink jet printer according to a first embodiment of the present invention. As shown, the inkjet printer of the first embodiment includes an inkjet head portion 10 and a paper feeding portion 20 for feeding printing paper P into the inkjet head portion 10.

In the inkjet head portion 10, a jet nozzle 12 for injecting ink onto the printing paper P is arranged. The jet nozzles 12 are arranged long enough along the longitudinal direction of the ink jet head 10 so as to jet ink to all the areas of the printing paper P which are fed obliquely by the sheet feeding unit 20. The inkjet head unit 10 prints predetermined print data supplied from the print data supply unit 14 on the printing paper P.

The paper feeding unit 20 inclines the printing paper P such that the printing paper P is inclined at a predetermined angle between the central axis direction A of the printing paper P and the horizontal direction B of the inkjet head 10 in the longitudinal direction. 10). The paper feeding unit 20 includes a traveling roller 22 for advancing the printing paper P to the inkjet head unit 10, and an inclination forming roller 24 for forming an inclination on the printing paper P.

The traveling roller 22 has a rotation axis parallel to the longitudinal direction (C) of the inkjet head unit 10, and rotates the printing paper P as the ink is supplied from a power supply unit not shown in the inkjet head unit 10. Proceed to).

The inclined forming roller 24 is provided between the inkjet head portion 10 and the traveling roller 22. The inclined forming roller 24 has a rotational axis in a direction C parallel to the rotational axis of the progressing roller 22, and an extension line in the direction D having the inkjet head portion 10 in a longitudinal direction and a predetermined angle a '. At least two are arranged on the phase. The inclined forming roller 24 allows the printing paper P to proceed after the printing paper P is allowed to be inclined in the extension line direction D so that the entry side of the printing paper P to the inkjet head portion 10 is inclined. It is formed to be.

The inclination forming roller 24 includes a first inclination forming roller 24a, a second inclination forming roller 24b, and a third inclination forming roller 24c. Each inclined forming roller 24 is arranged along the extension line direction D, so that the first inclined forming roller 24a is located closest to the traveling roller 22, and the third inclined forming roller 24c is traveling. It is located farthest to the roller 22. Although the three rollers are provided in the inclination forming roller 24 shown in FIG. 2, it is preferable that the inclination forming roller 24 is provided with a plurality of rollers.

The contact surface with the printing paper P of the inclination forming roller 24 is formed convexly. Thereby, the inclination-forming roller 24 makes it easy to incline the printing paper P at a predetermined angle by making point contact with the printing paper P.

The measuring unit 30 measures the actual inclination angle a between the central axis of the printing paper P fed by the paper feeding unit 20 and the horizontal direction of the length of the inkjet head unit 10. The measurement unit 30 includes a first sensor 32 and a second sensor 34 spaced apart by a predetermined distance in the longitudinal direction of the inkjet head unit 10. The measurement unit 30 is a difference between the time when the approach of one side of the printing paper P is recognized by the first sensor 32 and the time when the approach of the other side of the printing paper P is recognized by the second sensor 34. And the inclination angle a between the central axis direction A of the printing paper P and the horizontal direction B of the length of the inkjet head portion 10 based on the traveling speed of the printing paper P. The first sensor 32 and the second sensor 34 may be an optical sensor, a contact sensor, or various other sensors. The measuring unit 30 may be any other conventional sensor means as long as it can measure the inclination angle a of the printing paper P.

The adjusting unit 40 receives the inclination angle a from the measuring unit 30 and print data supply unit 14 so as to be suitable for the printing paper P which is inclinedly fed to the inkjet head unit 10 based on the inclination angle a. ) Adjusts the print data supplied to the inkjet head portion 10. As a result, the inkjet head unit 10 prints the print data on the printing paper P to form a predetermined image.

The inkjet printer according to the first embodiment discharges the printing paper P printed by the inkjet head 10, while the axis of the printing paper P is in the horizontal direction B of the length of the inkjet head 10. It is preferable to include a discharge unit (not shown) for removing the inclination of the printing paper (P) to match the. The discharge unit (not shown) may have a configuration similar to that of the paper feeder 20.

Hereinafter, the operation of the inkjet printer according to the first embodiment of the present invention will be described. When the printing command is received, the progress roller 22 picks up the printing paper P of the printing paper cassette (not shown) to the inkjet head portion 10 in a direction S parallel to the horizontal direction B of the length of the inkjet head portion. Proceed.

By the rotation of the advancing roller 22, the entry side of the printing paper P comes into contact with the first inclination forming roller 24a, the second inclination forming roller 24b, and the third inclination forming roller 24c. . At this time, each of the inclination-forming rollers 24 is not rotated or fixed in a direction opposite to the rotation direction of the traveling roller 22 until one side of the printing paper P comes into contact with the third inclination-forming roller 24c. By rotating, the entry side of the printing paper P is inclined in the extension line direction D. As shown in FIG.

When the entry side of the printing paper P is inclined in the extension line direction D, each of the inclination-forming rollers 24 rotates in the same direction as the traveling roller 22 at the same time to turn the printing paper P into the inkjet head portion 10. Proceed. By this process, the printing paper P is fed to the inkjet head portion 10 in the horizontal direction S of the length of the inkjet head portion 10 in an inclined angle.

The measurement unit 30 actually measures the inclination angle a of the inclined printing paper P and transmits information about the inclination angle a to the adjustment unit 40, and the adjustment unit 40 is based on the inclination angle a. The inkjet head portion 10 adjusts the print data so as to print a predetermined image. The inkjet head portion 10 prints the adjusted print data on the printing paper P fed by being inclined by the inclination angle a.

Accordingly, the jet nozzle 12 which jets ink onto portions of the adjacent portions of the printing paper P to form image pixels is continuously changed. That is, ink to be sprayed onto the printing paper P to form image pixels adjacent to each other is continuously sprayed by the other spray nozzles 12. Accordingly, the injection nozzle 12 disposed at the specific position of the inkjet head portion 10 is moved from the entry side of the printing paper P to the opposite side to the portion of the printing paper P at the position corresponding to the injection nozzle 12. Ink is jetted continuously to prevent the formation of image pixels on the printing paper P.

Even when the performance of the specific jet nozzle 12 is deteriorated, adjacent image pixels are continued by the jet nozzle 12 whose performance is degraded by distributing the charge jet nozzle 12 so as to be printed by another jet nozzle 12. Can be prevented from being degraded as a whole.

When the printed image is 1200 dpi, when the A4 print paper is inclined by 1 cm, it is changed by about 30 dots, which shows a difference of 0.6 mm on the printed image. This may have an effect similar to shingling of a conventional shuttle type printer.

The inkjet printer according to the first embodiment of the present invention may further include a conveying unit (not shown). The conveying unit (not shown) is provided to convey the printing paper P printed by the inkjet head unit 10 to the paper feeding unit 20 again. The paper feeding unit 20 feeds the printing paper P conveyed by the conveying unit (not shown) to the inkjet head unit 10 again. The printing paper P may be repeatedly fed into the inkjet head unit 10 by the paper feeding unit 20 and the conveying unit (not shown), and predetermined print data may be shuffled and printed. At this time, it is preferable that the paper feeding unit 20 feeds the printing paper P at different inclination angles.

Hereinafter, a shingling printing process by repeat feeding will be described. The adjusting unit 40 shuffles the print data into the first print and the second print. During the first printing, the inclination-forming roller 24 is rotated in the same direction as the idle state or the progress roller 22 so as not to interfere with the progress of the printing paper P. Thereby, the printing paper P is fed without being inclined. At this time, it is preferable that the measurement unit 30 omits the inclination angle measurement, and the adjustment unit 40 does not adjust the print data for the first printing.

When the inkjet head portion 10 prints the first print, the conveying portion (not shown) conveys the printing paper P back to the sheet feeding portion 20. The paper feeding unit 20 feeds the printing paper P received in order to print the second printing portion back to the inkjet head unit 10. During the second printing, the inclination-forming roller 24 feeds the printing paper P to the inkjet head portion 10 by inclining the predetermined angle by preventing the printing paper P from advancing. The measurement unit 30 measures the inclination angle, and the adjustment unit 40 adjusts the print data of the second printing portion according to the inclination angle measured by the measurement unit 30. The inkjet head unit 10 prints the print data of the adjusted second print. Thus, a predetermined image is printed on the printing paper P through two shingling printing.

On the contrary, when printing the first printing powder, the paper can be fed obliquely, and the printing data can be adjusted and printed accordingly, and the printing of the second printing powder can be fed without tilting and printing without adjusting the printing data.

When the driving unit (not shown) for changing the arrangement direction of the inclination forming roller 24 is further provided, three or more shingling printing is possible. The paper feeding unit 20 may change the inclination angle of the printing paper fed by changing the arrangement direction of the inclined forming roller 24 by a driving unit (not shown), and the adjusting unit 40 corresponds to the number of times of repeated feeding. The print data can be shuffled and the print data of the print can be adjusted to suit each tilt angle.

Through repeated feeding through different angles of inclination and shingling of print data, it is possible to further disperse the risk of deterioration in print quality due to deterioration of performance of a particular jet nozzle.

3 and 4 are schematic diagrams showing an ink jet printer according to a second embodiment of the present invention. Components having the same construction and function as the first embodiment of the present invention are given the same reference numerals and detailed description thereof will be omitted. As shown, the inkjet printer according to the second embodiment has a paper feeding direction S for feeding the printing paper P to the inkjet head portion 10 in a horizontal direction B of the length of the inkjet head portion 10. It is provided with a paper feeding portion 20 'for feeding to achieve a predetermined angle (b).

The paper feeding portion 20 'includes an access roller 26 and a paper feeding direction changing roller 28. The access roller 26 has a rotation axis in the direction C parallel to the longitudinal direction of the inkjet head portion 10, and accesses the printing paper P to the inkjet head portion 10. As shown in FIG.

The paper feed direction changing roller 28 is located between the inkjet head portion 10 and the access roller 26, and has a rotation axis in the direction E having the rotation axis of the access roller and a predetermined angle b '. The paper feeding direction changing roller 28 receives the printing paper P from the approach roller 26, and has a paper feeding direction S having a horizontal direction B of the length of the inkjet head portion 10 and a predetermined angle b. ), The printing paper P is fed into the inkjet head portion 10.

The contact surface of the paper feed direction changing roller 28 with the printing paper P is preferably formed convex so as to be in point contact with the printing paper P. The feeding direction changing roller 28 may be provided with at least one roller, but a plurality of rollers are preferably provided. When a plurality of feeding direction changing rollers 28 are provided, they may be arranged in the direction parallel to the rotation axis direction C of the access roller 26 or in other directions, but are preferably arranged along the rotation axis direction E. Do.

The measuring unit 30 ′ measures the paper feeding angle b between the paper feeding direction S of the printing paper P and the horizontal direction B of the length of the inkjet head 10. The adjusting unit 40 'adjusts the print data according to the feeding angle b so as to be suitable for the printing paper P fed at an angle.

The measuring unit 30 'extends in the longitudinal direction C of the inkjet head unit 10 and is disposed to be transversely on the traveling path of one edge portion on the entry side of the printing paper P. As the printing paper P is fed in the feeding direction S, the feeding angle b is measured based on the rate of decrease or increase per hour of the length overlapping with the printing paper P and the feeding speed of the printing paper P. . The measuring unit 30 'can measure the feeding angle b by other conventional means.

It may further include a discharge unit (not shown) for discharging the printing paper (P) printed by the inkjet head 10 in a direction parallel to the horizontal direction (B) of the length of the inkjet head 10.

Hereinafter, the operation of the inkjet printer according to the second embodiment of the present invention will be described. When the printing command is received, the printing paper P is picked up from the printing paper cassette (not shown) by the rotation of the access roller 26 and transferred to the paper feed direction changing roller 28. When the printing paper P is transferred to the feeding direction changing roller 28, the access roller 26 is in an idle state, and the printing paper P is inkjet in an oblique direction S by the rotation of the feeding direction changing roller 28. It is fed to the head part 10.

The measuring unit 30 'measures the actual feeding angle b of the printing paper P and transmits the feeding angle b value to the adjusting unit 40', and the adjusting unit 40 'is adjusted according to the feeding angle b. Adjust the print data. Through this process, the inkjet head unit 10 may continuously form image pixels adjacent to each other on the printing paper P by using the other jet nozzles 12.

The inkjet printer according to the second embodiment of the present invention may include a conveying unit (not shown) similarly to the inkjet printer according to the first embodiment described above. Accordingly, print data can be shuffled and printed. Further comprising a drive unit (not shown) for changing the rotation axis of the paper feed direction changing roller 28, repeated feeding and adjustment unit 40 'by different feeding directions by the action of the conveying unit (not shown) and the paper feeding unit 20'. 3 or more shingling prints are possible by adjusting the print data according to the shingling and feed angle.

 As described above, the inkjet printer according to the present invention improves the overall print quality by minimizing the degradation of print quality that may be caused by the spray nozzle which is partially deteriorated by feeding the print paper in an oblique direction or feeding in an oblique direction. You can.

Claims (7)

An inkjet printer comprising an inkjet head portion for arranging a jet nozzle for injecting ink onto printing paper, and printing predetermined print data on the printing paper. A paper feeder which feeds the printing paper to the inkjet head portion inclined such that the central axis of the printing paper and the horizontal direction of the length of the inkjet head portion cross at a predetermined angle; A measuring unit for measuring an inclination angle between the central axis of the printing paper fed by the paper feeding unit and the horizontal direction of the length of the inkjet head portion; And an adjusting unit for adjusting the print data according to the inclination angle measured by the measuring unit so as to be suitable for the printing paper fed obliquely. The method of claim 1, The paper feeding unit, A traveling roller having a rotational axis parallel to a lengthwise direction of the inkjet head portion, for advancing the printing paper to the inkjet head portion; Located between the inkjet head portion and the traveling roller, having a rotation axis parallel to the rotation axis of the traveling roller, arranged on an extension line crossing the length direction of the inkjet head portion, the entry of the printing paper into the inkjet head portion And a plurality of inclination-forming rollers formed so as to advance the printing paper after the advancing of the printing paper such that the sides thereof are inclined in the extension line direction. The method of claim 2, The inclined forming roller is an inkjet printer, characterized in that the contact surface with the printing paper is formed to be convex and in point contact with the printing paper. The method according to any one of claims 1 to 3, A conveying unit for conveying the printing paper printed by the inkjet head unit to the paper feeding unit, The paper feeding unit receives the printing paper from the conveying unit and repeatedly feeds the printing paper to the inkjet head unit at different angles, And the adjusting unit shuffles the print data and adjusts each of the shuffled print data according to the different angles. An inkjet printer comprising an inkjet head portion for arranging an injection nozzle for injecting ink onto a printing paper and receiving printing data to print on the printing paper. A paper feeder for feeding the printing paper into the inkjet head portion such that the paper feeding direction of the printing paper to the inkjet head portion crosses the horizontal direction of the length of the inkjet head portion at a predetermined angle; A measuring unit for measuring a feeding angle between the feeding direction of the printing paper and the transverse direction of the length of the inkjet head unit by the feeding unit; And an adjusting unit for adjusting the print data according to the feeding angle so as to be suitable for the printing paper fed in an oblique direction. The method of claim 5, The paper feeding unit, An access roller having a rotational axis parallel to the lengthwise direction of the inkjet head portion, and accessing the printing paper to the inkjet head portion; A feeding direction changing roller positioned between the ink jet head portion and the access roller, having a rotation axis intersecting the rotation axis of the access roller, and configured to receive the printing paper from the access roller and to feed the ink to the ink jet head portion; Inkjet printer comprising a. The method according to claim 5 or 6, A conveying unit for conveying the printing paper printed by the inkjet head unit to the paper feeding unit, The paper feeding unit receives the printing paper from the conveying unit and repeatedly feeds the printing paper in the inkjet head unit in different directions, And the adjusting unit shuffles the print data and adjusts each of the shuffled print data according to the different directions.

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